A mob-linked Manhattan “boiler room” that swindled elderly people out of about $12 million by getting them to buy a hyped-up stock was shut down today by the FBI.

Federal authorities busted seven people in New York, New Jersey and Florida and were looking for six more suspects involved in the in the financial scam, which operated out of offices in a Garment District building on W. 36th St under the name Powercom Energy Services.

The defendants – who included Bonnano crime family “soldier” Anthony Guarino – are expected to appear today in Manhattan federal court.

Law enforcement sources said the defendants would “cold call” elderly people who lived outside New York and offer them the chance to invest in a Florida company that purportedly was working on developing high-speed and streaming video.

The calls were made to people who were not likely to inspect the company’s location before investing in the venture, sources said.

Victims would be left holding stock that dropped dramatically in value after buying it from people who were in on the scam.

FBI agents today hauled out more than a dozen boxes of evidence from the office, along with five computers.

Workers at the same office building said the boiler room, which was located on the sixth floor, had been operating for three or four years.

A worker at the building who knew said that he had thought the firm was involved in oil investments. He also said the office was staffed by about eight men.

Maria Cruz, who works as a secretary for the Columbia Mutual Life Insurance Company, which is on the same floor as the boiler room, said, “To be honest with you, we never knew what kind of work they did.”

“One of them dressed like a gangster,” she said. “They were kind of scary-looking. One looked just like Howard Stern. At times we were afraid to be alone while they were here.”

“They didn’t look like business types,” Cruz said.

“Sometimes they didn’t come in at all, and other times they stayed late at night,” Cruz.